Muchas gracias por su ayuda!
Dejo el la aplicacion funcionando para futuras consultas.
<script language="javascript">
function cambiarHref(pais, region)
{
pais=pais.replace(/\s+/g,"-");
var new_pais = pais.toLowerCase();
region=region.replace(/\s+/g,"-");
var new_region = region.toLowerCase();
if(new_region == "cuba" || new_region == "mexico" || new_region == "antarctica" )
{
//document.links[newpais].href = "/region/" + new_pais + ".htm";
document.location.href = "http://contourstravel.com.au/region/" + new_pais + ".htm";
}
else
{
//document.links[newpais].href = "/region/" + new_region + "/" + new_pais + ".htm";
document.location.href = "http://contourstravel.com.au/region/" + new_region + "/" + new_pais + ".htm";
}
}
</script>
</head>
<body>
<a href="javascript
:cambiarHref('The Bahamas', 'caribbean')" name="tag_pais">tag_pais</a>